h1, h2, h3, h4, h5, h6 {
  margin: 0.5em 0 0.5em;
  padding: 0;
  font-weight: bold;
  line-height: 150%;
  overflow: hidden;
}

h1 {
  font-size: 2.3em; /* 45px */
}

h2 {
  font-size: 2.0em; /* 35px */

  padding: 3px 8px;
  border-radius: 5px;

  /********* 参考 IBM Developerworks ****************/
  background-color: #595c64;
  filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#595c64', endColorstr='#1b1b1c'));
  background: -webkit-gradient(linear, left top, left bottom, from(#595c64), to(#1b1b1c));
  background: -moz-linear-gradient(top, #595c64, #1b1b1c);
  background: -o-linear-gradient(top, #595c64, #1b1b1c) transparent;
  color: #ccc;

  letter-spacing: 0;
  text-decoration: none;
  text-shadow: 0 -1px 0 #000;
}

h3 {
  font-size: 1.9em; /* 32px */
}

h4 {
  font-size: 1.7em; /* 28px */
}

h5 {
  font-size: 1.5em; /* 25px */
}

h6 {
  font-size: 1.3em; /* 22px */
  color: #777;
}

h1 code, h2 code, h3 code, h4 code, h5 code, h6 code {
    background-color: inherit;
    border: none !important;
    font-size: inherit;
}

h2 code {
    color: #ccc;
}

kbd {
    display: inline-block;
    margin: 0 .1em;
    padding: .1em .6em;
    font-family: Arial,"Helvetica Neue",Helvetica,sans-serif;
    font-size: 11px;
    line-height: 1.4;
    color: #242729;
    text-shadow: 0 1px 0 #FFF;
    background-color: #e1e3e5;
    border: 1px solid #adb3b9;
    border-radius: 3px;
    box-shadow: 0 1px 0 rgba(12,13,14,0.2),0 0 0 2px #FFF inset;
    white-space: nowrap;
}

hr {
    border: 0;
    border-bottom: 1px dashed #cfcfcf;
    margin: 1em 0;
}
